The present invention relates to a process to make polyethylene through homopolymerization or copolymerization of ethylene with alpha-olefins in the presence of a titanium amide catalyst on an organic polymer carrier for the production of moldings through extrusion, injection molding, film blowing-extrusion, sintering under pressure or ram extrusion. Further, the invention relates to a titanium amide catalyst on an organic polymer carrier, and its manufacture.
It is known that organometallic catalysts for the polymerization of ethylene based on titanium amides, which were contacted with aluminorganic or magnesium-organic compounds prior to their addition to the polymerization system, yield polyethylenes with long-chain branchings in the polymer molecules (A. Imai, H. Shiraishi, H. Jouhouji: Studies in Surface Science and Catalysis 92 (1995) 299 ff.). Such long-chain branched polyethylenes are characterized by a number of new and interesting properties. These include, among others, an improved processability at common shearing speeds as compared to conventional polymers, at similar densities and similar melt flow index (MFI) due to a dynamic viscosity of the polymers decreasing with an increasing degree of long-chain branching (A. Batistini: Macromol. Symp. 100 (1995) 137 ff.). To make efficient practical use of such specific catalysts for producing polyethylene, it is often necessary to fix the catalyst components on a suited carrier. This can be done through various processes using special inorganic carriers (EP 320 169). Carrier-based catalyst systems, however, are disadvantageous inasfar as they have to undergo a high-temperature treatment for conditioning or as they may cause corrosion on the polymer processing machines due to residual chlorine remaining in the polymers produced, or as they may cause undesired processing phenomena, such as specks or pinholes, due to inorganic carrier remaining in the polymer.
It is the intention of the invention to develop a process for making polyethylene through homopolymerization or copolymerization of ethylene with alpha-olefins in the presence of a titanium amide catalyst on an organic polymer carrier, and a titanium amide catalyst on an organic polymer carrier, which do not show the known disadvantages and which are characterized by a high polymerization activity, a low catalyst residual content, and a good polymer color as well as efficient production.
According to the invention, polymerization to produce polyethylene through homopolymerization or copolymerization of ethylene with alpha-olefins is initiated by
1. a titanium amide catalyst on an organic polymer carrier with
a) a partly chloromethylated styrene divinyl benzene copolymer with
a divinyl benzene content of 1 to 45 percent by weight,
a chlorine content of 5 to 23 percent by weight,
a specific surface area of 5 to 1,000 m2/g, and
a particle size of 50 to 3,000 xcexcm as the organic polymer material
b) a complex compound supported by the above organic polymer material, with the general formula of
(RmMgX2xe2x88x92m)xc2x7(RnAlY3xe2x88x92n)pxc2x7(XqTiL4xe2x88x92q)xc2x7EDr
xe2x80x83whereby:
R=alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl
X=halogen
Y=hydrogen, halogen, alkoxy
L=dialkylamido, dicycloalkylamido, diarylamido, diaralkylamido, dialkarylamido or mixed
ED=organic compound acting as electron donor, such as linear or cyclic ethers, thioethers or others
m=1 or 2
n=numerical value 1 through 3
p=numerical value 0.1 to 1
q=0, 1, 2 or 3
r=numerical value 1 to 2
c) the conversion product of the complex compound supported by the organic polymer material of b) with a mixture of
A) a compound of the general formula of
XmTiY4xe2x88x92m
xe2x80x83whereby
X,
Y=halogen, alkyl, aryl, alkaryl, aralkyl, alkoxy, aroxy
m=1, 2, 3 or 4and
B) a compound of the general formula of
RnCX4xe2x88x92n
xe2x80x83whereby
R=hydrogen, alkyl, aryl, alkaryl, aralkyl, chloromethyl, dichloromethyl, trichloromethyl or partially halogenated alkyl
X=halogen, alkyl, alkenyl, aryl, alkaryl, aralkyl, alkoxy, aroxy
n=0, 1, 2 or 3
with a molar ratio of the compounds A) and B) in the range of 1:0.1 to 1:2
whereby the starting substrate for the compound supported by the organic polymer material at b) is made through intensive grinding and mingling of the organic polymer material with the transition metal compound below the glass transition temperature of the polymer under anaerobic conditions, and
2. a compound of the following general formula acting as an activator
RmAlY3xe2x88x92m
xe2x80x83whereby
R=alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkenyl
Y=hydrogen, halogen, alkoxy
m=numerical value of 1 to 3.
According to the invention, a partly chloromethylated styrene divinyl benzene copolymer with
a divinyl benzene content of 2 to 25 percent by weight,
a chlorine content of 15 to 22.5 percent by weight,
a specific surface of 10 to 300 m2/g, and
a particle size of 80 to 2,000 xcexcm
can be used as the organic polymer material.
According to the invention, triisobutyl aluminum can be used as the compound acting as activator. In accordance with the present invention, tetrakis-(diethyl amido) titanium can be used as the transition metal compound for the starting substrate made through intensive grinding and mingling with the organic polymer material for the compound supported by the organic polymer material. According to the invention, the polymer made through homopolymerization or co-polymerization of ethylene with alpha-olefins in the presence a titanium amide catalyst supported by an organic polymer carrier can have viscosity numbers from 150 to 3,000 ml/g. In accordance with the present invention, the titanium amide catalyst supported by an organic polymer material contains
a) a partly chloromethylated styrene divinyl benzene copolymer as the organic polymer material, with:
a divinyl benzene content of 1 to 45 percent by weight,
a chlorine content of 5 to 23 percent by weight,
a specific surface of 5 to 1,000 m2/g, and
a particle size of 50 to 3,000 xcexcm,
b) a complex compound supported by the organic polymer material of the following general formula
(RmMgX2xe2x88x92m)xc2x7(RnAlY3xe2x88x92n)pxc2x7(XqTiL4xe2x88x92q)xc2x7EDr
xe2x80x83whereby:
R=alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl
X=halogen
Y=hydrogen, halogen, alkoxy
L=dialkylamido, dicycloalkylamido, diarylamido, diaralkylamido, dialkarylamido or mixed
ED=organic compound acting as electron donor, such as linear or cyclic ethers, thioethers or others
m=1 or2
n=numerical value of 1 to 3
p=numerical value of 0.1 to 1
q=0, 1, 2 or 3
r=numerical value of 1 to 2
c) the conversion product of the complex compound at b) supported by the organic polymer material, with a mixture of
A) a compound of the general formula of
XmTiY4xe2x88x92m
xe2x80x83whereby
X, Y=halogen, alkyl, aryl, alkaryl, aralkyl, alkoxy, aroxy
m=1, 2, 3 or 4, and
B) a compound of the general formula of
RnCX4xe2x88x92n
xe2x80x83whereby
R=hydrogen, alkyl, aryl, alkaryl, aralkyl, chloromethyl, dichloromethyl,
trichloromethyl or partially halogenated alkyl
X=halogen, alkyl, alkenyl, aryl, alkaryl, aralkyl, alkoxy, aroxy
n=0, 1, 2 or 3
with a molar ratio of compounds A) to B) in the range of 1:0.1 to 1:2,
whereby:
the starting substrate for the compound at b) supported by the organic polymer material is made through intensive grinding and mingling of the organic polymer material with the transition metal compound below the polymer""s transition temperature under anaerobic conditions, and
the titanium amide catalyst supported by the organic polymer material is activated by a compound of the following general formula
RmAlY3xe2x88x92m
xe2x80x83whereby:
R=alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkenyl
Y=hydrogen, halogen, alkoxy
m=numerical value of 1 to 3.
According to the present invention, this catalyst can be made from the components of claim 6, through conversion in the order mentioned therein.